Liquid Crystal Display (LCD) and Organic Light-Emitting Diode (OLED) displays have advantages of low radiation, small size, low power consumption, etc. Therefore, LCD and the OLED displays have been widely used in notebook computers, Personal Digital Assistants (PDAs), flat-screen TVs, mobile phones and other products.
Products integrating touch technology with display technology have gradually spread into people's lives. Currently, touch screens can be classified as out-cell touch screen, surface-covering touch screen, or in-cell touch screen according to their structures. In the in-cell touch screen, touch electrodes of the touch screen are embedded inside a display panel, so that an overall thickness of the module can be reduced, and manufacturing cost of the touch screen can be reduced. Conventional in-cell capacitive touch screens detect a finger touch position based on a mutual capacitance principle or a self capacitance principle. In the self capacitance principle, a plurality of self-capacitance electrodes, which are insulated from each other, are disposed in a same layer. When the touch screen is not touched, each self-capacitance electrode is applied with a constant capacitance, and when the touch screen is touched, the corresponding self-capacitance electrode is applied with the constant capacitance superimposed with a body capacitance. A touch detection chip is used to detect capacitance change of each self-capacitance electrode, so as to detect a touched position.
With the increase of the display panel size, lengths of signal lines used in the touch display panel are increased. Therefore, resistances and capacitances of the signal lines increase, and differences of the resistances and capacitances between different signal lines increase, which results an increase of RC delay of the display panel, where R represents resistance, C represents capacitance, and RC represents a product of the resistance and the capacitance. The increase of the RC delay further results degradation of display performance and touch performance